Experimental system may help type 1 diabetics avoid nighttime complications

A computer program that predicts dangerous low blood sugar levels in type 1 diabetics while they sleep averted more than half of the usual number of episodes in a small trial.

The experimental system linked to an implanted monitor may help people with type 1 diabetes avoid nighttime seizures and other complications brought on by prolonged periods of low blood glucose, or hypoglycemia, according to the study’s lead author.

“The goal of this study was to have the system work in the background, without generating unnecessary alarm, so people can get a good night’s sleep and not be at risk for prolonged low blood glucose,” Dr. Bruce Buckingham, one of the study's authors, said.

Buckingham is a specialist in pediatric endocrinology at the Stanford University School of Medicine in Stanford, California.

The system wirelessly connects through a bedside computer to a blood sugar monitor implanted under the skin and a wearable insulin delivery pump. The program analyzes data from the monitor and shuts off the insulin pump when it predicts that a person’s blood sugar is going to dip too low.

Type 1 diabetes, previously known as juvenile diabetes, typically strikes children whose immune systems have killed off insulin-producing cells in the pancreas. The body needs insulin to remove sugar from the blood to use for energy.

Diabetics can control their blood sugar during the day by regulating their insulin use and food intake. But at night, an automatic insulin pump may drive blood sugar levels too low.

Buckingham and his colleagues write in Diabetes Care that past research shows about 9 percent of people with type 1 diabetes experience hypoglycemia at night.

The researchers recruited 45 people with diabetes between the ages of 15 and 45 to use the system for 42 nights.

The system randomly selected half of the nights to run its calculations and the other half to remain dormant for comparison.

The system shut off the insulin pump when it predicted that a person’s blood sugar would fall below 80 milligrams per deciliter (mg/dL) of blood in the next 30 minutes. A person starts to be at risk from complications of low blood sugar at 60 mg/dL.

The pump was shut off until the person’s blood sugar began to rise.

The researchers found that a blood sugar reading of 60 mg/dL was recorded on 21 percent of the nights the system was active, compared to 33 percent of the nights when it was dormant.

Overall, the researchers found the average time people spent with low blood sugar was reduced by 81 percent during the nights the system was active, compared to when it was inactive.

The participants’ blood sugar readings tended to be higher after nights when the system was active, but did not reach dangerously high levels, the researchers write.

“This technology can work,” Buckingham said. “It can decrease the risk of having a prolonged low at night and there seems to be minimal downside.”

He added that studies like this one are the first step toward creating artificial pancreases, which would be able to reliably stop and start delivering insulin around the clock.

“This is just demonstrating that if used properly . . . what they’re able to do is prevent hypoglycemia, which is one of the two biggest issues with diabetes safety,” Dr. Steven Willi told Reuters Health.

Willi, who was not involved in the new study, directs the Diabetes Center for Children at The Children’s Hospital of Philadelphia.

“This is a ripe target, but it’s just a step along the road to having a fully automated device,” he said.